Fluorogenic sensing of mitochondrial electron transferring dehydrogenase using a trimethyl lock quinone-linked hemicyanine

Abstract

A trimethyl lock quinone (TLQ)-linked hemicyanine (probe 1) is developed for imaging mitochondrial dehydrogenase activity in the live human cells. In aqueous environment, the system underwent a fluorogenic reduction of TLQ moiety upon incubation with human recombinant NQO1, providing a fluorescence Off-On with a concomitant visual color change from yellow to orange. In contrast to other TLQ-based fluorescent probes, probe 1 is localized to the mitochondria of living cells where little NQO1 exist. And, it can provide a fluorescence turn-on response which was selectively modulated by antimycin A and myxothiazol, a potent inhibitor of the complex III in the electron transfer chain and showed poor response to dicoumarol, a potent inhibitor of NQO1. Likely, probe 1 acts as a fluorogenic chemosensor for the mitochondrial electron transferring reaction in the live cells.